Abstract: The present invention provides an oil detecting element capable of accurately detecting oil floating on water. The oil detecting element comprises a water-repellent, oil-passing filtering member for preventing water coming into the element. Oil can be detected by detecting change in electric resistance of a conductive particle layer due to its contact with oil arriving through the member. According to an embodiment of the invention, the water-repellent, oil-passing filtering member is impregnated with a material which is toxic to water life such as algae and shells to prevent settling of these water life on the surface of the element and thereby to prolong the life of the element. Examples of an oil detector incorporating the oil detecting element and including an electrical circuit which detects change in electric resistance of the element upon its contact with oil and actuates a suitable alarming device such as a buzzer are described.

Abstract: A dialysis unit and a dialysis apparatus employing the dialysis unit which can perform dialysis at a very high efficiency. The unit comprises a vast plurality of semi-permeable hollow fibers substantially equal in length, which fibers are gathered to form a bundle and bonded in liquid-tight connection at both ends portions thereof. This bundle of hollow fibers is loosely encased in a casing having a plurality of openings substantially uniformly distributed all over the casing. The dialysis unit is put in a dialyzate bath having therein a means for making a forced current of the dialyzate. The dialyzate flows into the casing through the openings and acts upon the bundle of hollow fibers from all directions. Accordingly, the dialyzate can flow freely inside and outside the bundle, while maintaining good contact between the dialyzate and the surfaces of the fibers, even in the inner portion of the bundle.

Abstract: Apparatus of all types for the separation of fluids which comprise at least one semi-permeable tubular membrane mounted on a porous support, the membrane being kept out of contact with adjacent parts of the apparatus by at least one thread-like element wound spirally around the membrane.

Abstract: For obtaining coalescence of particles suspended in a carrier liquid, a plurality of relatively small bodies are circulated in a closed cycle together with a part of the suspension, and in the narrower interspaces between said bodies and on the surfaces thereof the probability of particles meeting one another is increased. Carrier liquid with suspended coalesced particles is continuously withdrawn from the closed cycle, and fresh liquid is continuously introduced therein, the circulating movement of the bodies being maintained either by the kinetic energy of the introduced liquid or by injecting an auxiliary driving medium into the liquid flow.